Rohaite is a rare thallium lead potassium sulfosalt. It occurs in veins cutting an alkalic intrusive. Associated minerals include chalcocite, cuprite and analcime. It was first described from material found in Denmark (Greenland).

Hardness

3-3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareSulfosalt family

Rohaite

Hardness: 3-3.5
Luster: Metallic
Streak: Black
Transparency: Opaque

No image

Is this rohaite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch rohaite with a known reference. Rohaite sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: black.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: steel gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: euhedral crystals, microscopic crystals.

Often confused with

Rohaite vs. its common look-alikes, and how to tell them apart in the field.

mineral

Bornite

Mohs 3-3.25

How to tell apart: Streak differs, so Rohaite leaves black, Bornite leaves pale grayish black.

How to tell apart: Streak differs, so Rohaite leaves black, Chalcocite leaves blackish lead-gray.

Compare →

Often found alongside rohaite

Minerals reported to co-occur with rohaite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: (Tl,Pb,K)₂Cu₈.₇Sb₂S₄
Mohs hardness: 3-3.5
Density: 7.78 g/cm³
Colors: Steel gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Euhedral crystals, microscopic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In veins cutting an alkalic intrusive

Where rockhounds find rohaite

Classic worldwide localities

Ilímaussaq intrusion, southern Greenland (type locality)

Field-hunting tip

Where it forms: In veins cutting an alkalic intrusive. If you start seeing chalcocite, löllingite, cuprite in float, you are in the right ground. Typical habit: euhedral crystals, microscopic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify rohaite?+

Mohs hardness is 3-3.5. Luster: metallic. The streak is black. Common colors include steel gray.

Where is rohaite found?+

Notable localities include Ilímaussaq intrusion, southern Greenland (type locality).

Is rohaite safe to handle?+

Rohaite contains antimony, copper, lead and thallium and calls for real care. Contains copper and sulfides; avoid inhaling dust and wash hands thoroughly after handling specimens.

What rocks look like rohaite?+

Rohaite is most often confused with Bornite, Chalcocite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with rohaite?+

Rohaite commonly co-occurs with Chalcocite, Löllingite, Cuprite, Antimonian silver, Analcime, Sodalite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does rohaite form in?+

Where it forms: In veins cutting an alkalic intrusive. Working float back to the host body is the standard way to chase a fresh occurrence.

What is rohaite used for?+

Rohaite is used in collector.

Find rohaite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.